LauraG
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Posts posted by LauraG
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If you haven't been testing your Free Chlorine (FC) level to know that you've had enough for a residual before each soak, then I think you've answered your question. You probably got to a very low or zero chlorine level for too long a period of time so hot tub itch bacteria could then grow. Also, I'm not sure how you are switching between using bleach vs. using MPS. The MPS can supplement the bleach, but cannot ever replace it (since you don't have N2). So perhaps when you weren't using MPS, then you didn't use enough bleach and the chlorine got to a low level. This would make sense if your husband only got the rash recently after this switch to not using MPS occurred (when did your husband start getting his rash again?).
What were the readings before you got in the tub with your friends? How long has it been since the last water change? Do you do a high-level shocking after a water change?
You should do a decontamination procedure and then watch your chlorine levels more carefully. If I recall, your tub is rather small and you use it heavily so have a very high bather load and would need to replace the water sooner than most anyway, even using the Dichlor-then-bleach method.
If you look at the list of hot tub inicidents, most are due to low or no chlorine for a period of time, some are after 1-2 months of Dichlor-only use, and I think only one was with N2 but with low or no chlorine. The N2 is a good insurance policy if the chlorine gets too low. The problem with any "add every day" system is that you have to be really diligent and in your case it's extra difficult due to the very high bather load.
I forget -- are you using 50 ppm Borates? I think with your small spa and the large FC swings that it would be a good idea to prevent the pH from varying a lot.
Richard
The FC is tested on a daily basis, and I have never missed adding Purox daily. I suspect that for some reason that night, there just wasn't enough left in as we soaked..... I always add in more right afterwards, as well.
The tub is 380 gallons.
I do have a question for you. We did a water change in March. We gave it a good cleaning, used swirl away, and was able to buy 10 Mule Team Borax. I am not sure if I have 50 ppm Borates!!! How do I measure that? I was not sure about that, so I put in 19 Tablespoons, then a week later put in another 10 tablespoons. I do not have a really high bather load any longer. I am using MPS to supplement only,and had not used it for a couple of weeks, but shocked with purox. I still used enough Purox, I was very diligent.
Right now I am lowering the TA, which is 120.
Today's reading are FC 3.0 The usual reading before I add more Purox for the day.
pH 7.6
CC 1.0
TA 120 (as I said, I am lowering this as I type)
CH 120
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It has been a while since I've needed your help!! Things have been going quite smoothly with the hot tub, until last week. I had been following the 'plan' quite well and had no trouble at all. My husband has the rash that he had last winter, but I thought it was 'just him'. Last week (Wed) a couple of our friends were over, and the next day they both say that they were very ithcy and had rashes. I did not.
My readings were pretty good before we got in, I added Purox afterwards( the same routine that has worked all these months).
The only thing I can think of that I did NOT do was add MPS for a couple of weeks beforehand. I had been shocking with MPS weekly, but ran out , so just shocked with Purox. Do you think that the FC was too low by the end of the evening? The TA and the pH were fine just before we got in. I did not check while we were in, but we weren't in as long as usual. Perhaps 1.5 hours or so. I shocked with MPS on Thurs. and was in for quite a while on Sat. and no ill effects.... I feel kind of badly that my friends woke up itchy and scratchy! They called my husband and told him it was the Purox, and they can't come in the hot tub anymore.... I don't believe it was the Purox....but perhaps the 'lack' of it...?
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It has been a while since I've needed your help!! Things have been going quite smoothly with the hot tub, until last week. I had been following the 'plan' quite well and had no trouble at all. My husband has the rash that he had last winter, but I thought it was 'just him'. Last week ( Wed) a couple of our friends were over, and the next day they both say that they were very ithcy and had rashes. I did not.
My readings were pretty good before we got in, I added Purox afterwards( the same routine that has worked all these months).
The only thing I can think of that I did NOT do was add MPS for a couple of weeks beforehand. I had been shocking with MPS weekly, but ran out , so just shocked with Purox. Do you think that the FC was too low by the end of the evening? The TA and the pH were fine just before we got in. I did not check while we were in, but we weren't in as long as usual. Perhaps 1.5 hours or so. I shocked with MPS on Thurs. and was in for quite a while on Sat. and no ill effects.... I feel kind of badly that my friends woke up itchy and scratchy! They called my husband and told him it was the Purox, and they can't come in the hot tub anymore.... I don't believe it was the Purox....but perhaps the 'lack' of it...?
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Hi! Just wanted to let you know that we re-filled the tub on the 29th. We added the swirl away, wiped it all out, and refilled. It was rather painless. I followed your instructions, everything went smoothly. Today's test results are:
pH 7.4
TA 80
FC 6
CH 150
CC .5
CYA 30
I have switched to Purox, and the TA and pH are holding nicely. The Borates are making the water feel great too.
This time, Iadded things more slowly, and I'm getting much better with the testing!
Thanks to you, I am much more confident and of course the water in the tub is fantastic.
Hope you had a great Christmas, and thanks again for all of your help.
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We've got some nasty weather here, so we have yet to change the water. However the TA was 125 the pH went to plus 8, so I did the add acid, areate, add acid thing......and today, the TA is 75, and the pH was around 7.0 so I aerated for half an hour and the pH jumped back up over 8. Do you think that perhaps I should have left my TA around 100 so as to not get so much pH bounce?
I have added more acid, and I'm going to test in an hour or so again.
The reason your pH went over 8 is because 75 ppm TA is still too high for you. Your pH is rising from aeration, and a lower TA will help that. If you get your TA down around 60, your pH should be more stable. A TA of 100 will be much worse than 75.
I'm still wondering how your TA got so high. Have you been using Baking Soda to clean your spa? If so, I would stop that. You're getting too much in the water, and messing up your balance. Your TA (and pH) should stay realitivly the same, and not go up, if you don't use BK.
I don't know either, why the TA went up there, but as of last night it was stable at 75, and the pH wasn't rising too quickly. I am going to continue today to lower the TA. It is a good learning experience for me, as I am testing often and seeing the results rather quickly. I got my new 'shipment' needed for the Taylor Kit, so I am good to go. Soon, we will change the water. Before that though I will test my tap water and let you know, ok?
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Do you mean to shock to 10 ppm with Dichlor as I will be using that for the first few days.
Yes, when you first fill the tub, use Dichlor. 1 oz (2 tablespoons) should put you at ~12 ppm in a 380 Gal tub. Let the jets run for 30 min. Then check FC, note it, cover and let sit overnight without using it. 24 hours later check FC again. This will give you a good base line. As I said, I'm only using ~25% FC per day with no use. Assuming you'll be this low (and I believe you will), you should be around ~8 ppm FC the next day.
Remember to keep track of the Dichlor you use, so you know when you get to ~30 ppm CYA. That would be a total of 3 ounces (6 tablespoons). Afer you add a total of 6 TBS to your tub, you can check CYA to make sure you're around 30 ppm. Then switch to bleach.
Also, I forgot, what's your pH, TA and CH coming from your tap water again? You might want to check it to make sure before you fill. You can balance your water the day after you fill, if your tap water's pH isn't too far off.
Lastly, did you use a Spa Flush on your last refill? If not, you may want to consider it. It should break up any gunk in your pipes. With your bather loads, it couldn't hurt. Remove your filter before you use that stuff, and soak it overnight in a filter cleaner.
If you come up with a good plan before hand, the whole thing should go quick and easy.
We've got some nasty weather here, so we have yet to change the water. However the TA was 125 the pH went to plus 8, so I did the add acid, areate, add acid thing......and today, the TA is 75, and the pH was around 7.0 so I aerated for half an hour and the pH jumped back up over 8. Do you think that perhaps I should have left my TA around 100 so as to not get so much pH bounce?
I have added more acid, and I'm going to test in an hour or so again.
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The FC today was 4.0. However, I did go in earlier for about 15 min. so...
As far as the high bather load, it has settled down somewhat (especially this week) I'd say that it's about twice a week that there is an 'extreme' bather load on average now.
Well, the fact that you used it makes it a little hard to tell, but it doesn't seem like it's getting much better. I'd just use it, keep an eye on your FC and drain it the first chance you get. You'll be amazed by the feel of the new water.
After you refil it do another Chlorine Demand test before you use it. Shock to ~10 ppm FC, and measure again 24 hours later. That will give you a good base line. Then you can keep track of your CD, by doing a test once a week. If you find your CD to be rising too fast, you know to use more chlorine.
Do you mean to shock to 10 ppm with Dichlor as I will be using that for the first few days.
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I live north of Chicago and know what it is like to change water in the middle of winter. It is not as bad as it sounds.
I do the spa flush first, then let it drain. Sometimes I help it along by bailing with my 5 gal Home Depot bucket, sometimes not. As the water is draining I clean what needs to be cleaned and use the old water to rinse. Remember, the water is 100F and no matter how cold it is outside your hands will stay warm.
The fill water coming out of the spigot in this area is 55F in winter. There is no chance of that water freezing, even on a 0F day, in the time it takes to fill the water above where the heater can be used.
I stressed the first time I did a complete water change on a really cold day, but no more. You will find out what a non-issue it is once you do it.
Waiting for a mild day is always an option, but not a necessity.
Thanks for the help. I've discussed this with my husband and we think that we'll drain it just after Christmas when we're both off work.
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Richard and I are in full agreement here. If it were summer, I'd tell you to change the water tomorrow and be done with it. Being winter, I'll tell you to look out for the next mild day. The tub shouldn't have a problem refilling if you do as Richard suggests. However, I can't say the same for your husband.
One thing I will add is, and this is entirely up to you, you can continue to try to get your Chlorine Demand (CD) down. First, see what happens tomorrow. If it looks like your (CD) is going down (i.e. your FC is higher), you may still be able to "catch" up a little.
If you can catch up, at least you won't be using as much chlorine. It would be interesting to see if you can get your CD down (i.e. FC up). If it were me, I would do it just to find out. But I don't want you to waste your chemicals and reagents without knowing it may not work. Also, you can't use the tub while doing this, so you may just want to get as much use out of it as you can.
Either way, let us know the FC level tomorrow.
The FC today was 4.0. However, I did go in earlier for about 15 min. so...
As far as the high bather load, it has settled down somewhat (especially this week) I'd say that it's about twice a week that there is an 'extreme' bather load on average now.
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After I added 10 oz. of Purox and 1 oz. MPS and aerated for 15 min. the FC was 14.5 (it had been 2.0 before adding)
Today the FC was 4.5, yep.
I am getting some foam only while all jets are full blast, no waterline scum to speak of, just a little (about the same as always), I am looking for a date of when I changed the water, it was in November.
We haven't used the tub this week too much at all. The last day we used it was Tuesday.
The water does not feel sluggish at all, but perhaps the bubbles take a bit longer to dissipate. Honestly, the water does seem fine, quite nice actually.
I will shock it again tonight and see what happens tomorrow.
Shock FC to ~12, and use two ounces MPS. Then see what happens tomorrow.
If FC is still low, you're getting tired of shocking and you don't mind adding extra Purox to keep up, you could just deal with it until your next water change. You just need to be extra careful about letting your FC drop too low. Also, it may be difficult to make it through the whole winter without needing another water change.
I shocked it to 12, and put 50 grams of MPS in (which is almost 2 oz). This is probably quite tiresome for you, but it is helping me greatly!!! I don't mind at all. My daughter is calling me an incompetent mad scientist! LOL
I will be careful about the FC. I was getting worried as I am running out of R-0871, but I ordered a new supply. I am hoping that I won't run out before it arrives.
I spoke to my husband about a water change, and he is not too keen at all about doing it during the winter. He says it is not good for the hot tub.... (freezing up I guess) But I will wait for a mild day. It won't go above 0 here very often now. I'm sure it will be fine for a while anyway.
You don't mind that I keep on asking advice??? I don't want to become a huge nuisance.
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So, Nitro, I did everything you said last night, and today the FC is 4.5
CC 1.5 pH7.8. I checked the TA and it was not a brilliant red at 100, but with one more drop it was really red, so that makes it 125. Perhaps this is part of the problem?
Let me make sure I have it correct. Last night your FC was ~12 ppm???. You added 1 oz of MPS, let it run for 15 mins and closed it up. Today your FC is 4.5 ppm. This is a little better, but you still have a high chlorine demand.
Are you having problems with foam and/or waterline scum etc.? The chlorine could be working on oils, lotions etc., which take longer to break down. MPS should help this out.
You can try doing another shock tonight. i.e. FC to ~12 ppm and add another oz (or two) of MPS. Only let the jets run for 15 min to mix it before covering. I hate to have you keep shocking the tub, but the only way I see to get your chlorine demand down is to keep shocking it, or do a water change.
BTW, when did you change your water last? It could be that because you're using the tub so much, you're now ready for another water change. Have you noticed the water to be sluggish? Do the bubbles take a lot longer to dissipate?
After I added 10 oz. of Purox and 1 oz. MPS and aerated for 15 min. the FC was 14.5 (it had been 2.0 before adding)
Today the FC was 4.5, yep.
I am getting some foam only while all jets are full blast, no waterline scum to speak of, just a little (about the same as always), I am looking for a date of when I changed the water, it was in November.
We haven't used the tub this week too much at all. The last day we used it was Tuesday.
The water does not feel sluggish at all, but perhaps the bubbles take a bit longer to dissipate. Honestly, the water does seem fine, quite nice actually.
I will shock it again tonight and see what happens tomorrow.
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I checked the TA and it was not a brilliant red at 100, but with one more drop it was really red, so that makes it 125. Perhaps this is part of the problem?
Each drop in the TA test represents 10 ppm, not 25 ppm.
I used the 10mL sample, 5 drops means 125 right?
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Richard, I've been trying to order through Lowry's here in Canada, but it is hard to do it seems. I've emailed them, they make it pretty easy to order the entire kits.
Yeah, Canada is a special case since Taylor goes through Lowry and tftestkits.com is not allowed to sell directly through Canada -- any Taylor kits have to go through Lowry as the distributor for Canada. You can get Taylor test kits in Canada through Apollo here since they buy from Lowry's and it's not cheap, but at least with a kit they give you a magnetic stirrer for free.
Thanks Richard, you saved me a lot of time!! I've ordered what I needed.
So, Nitro, I did everything you said last night, and today the FC is 4.5
CC 1.5 pH7.8. I checked the TA and it was not a brilliant red at 100, but with one more drop it was really red, so that makes it 125. Perhaps this is part of the problem?
maybe chem geek has an idea....
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Richard, I've been trying to order through Lowry's here in Canada, but it is hard to do it seems. I've emailed them, they make it pretty easy to order the entire kits.
Yeah, Canada is a special case since Taylor goes through Lowry and tftestkits.com is not allowed to sell directly through Canada -- any Taylor kits have to go through Lowry as the distributor for Canada. You can get Taylor test kits in Canada through Apollo here since they buy from Lowry's and it's not cheap, but at least with a kit they give you a magnetic stirrer for free.
Thanks Richard, you saved me a lot of time!! I've ordered what I needed.
So, Nitro, I did everything you said last night, and today the FC is 4.5
CC 1.5 pH7.8. I checked the TA and it was not a brilliant red at 100, but with one more drop it was really red, so that makes it 125. Perhaps this is part of the problem?
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Richard, I've been trying to order through Lowry's here in Canada, but it is hard to do it seems. I've emailed them, they make it pretty easy to order the entire kits.
Yeah, Canada is a special case since Taylor goes through Lowry and tftestkits.com is not allowed to sell directly through Canada -- any Taylor kits have to go through Lowry as the distributor for Canada. You can get Taylor test kits in Canada through Apollo here since they buy from Lowry's and it's not cheap, but at least with a kit they give you a magnetic stirrer for free.
Thanks Richard, you saved me a lot of time!! I've ordered what I needed.
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Also, I have another question for ya..... I was going to order some replacement reagents and am having some trouble. I need R-0780 DPD powder R-0871 and CR-0004. I have found some sites, but the codes do not seem to match. The one site has R-0871 powder....strange indeed. I just don't want to order the wrong thing.
I didn't find this site until after I ordered my R-0871 so I can't vouch for them- but their prices are decent and they have the whole kit laid out on a single page- with 2oz bottles available for a lot of them.
http://www.poolcenter.com/taylor_test_kit_reagents.htm
Jim
Thanks Jim, I'm not sure if I can get it from there as I live in Canada. My question is when I see the R-0871 which is the titrating reagent (chlorine) and it is the drops . What comes up when I click on it is the powder (which I also need). Therefore i can't seem to find the R-0871 (which I really need). I must be tired or something.... sounds confusing eh?
Richard, I've been trying to order through Lowry's here in Canada, but it is hard to do it seems. I've emailed them, they make it pretty easy to order the entire kits.
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Also, I have another question for ya..... I was going to order some replacement reagents and am having some trouble. I need R-0780 DPD powder R-0871 and CR-0004. I have found some sites, but the codes do not seem to match. The one site has R-0871 powder....strange indeed. I just don't want to order the wrong thing.
I didn't find this site until after I ordered my R-0871 so I can't vouch for them- but their prices are decent and they have the whole kit laid out on a single page- with 2oz bottles available for a lot of them.
http://www.poolcenter.com/taylor_test_kit_reagents.htm
Jim
Thanks Jim, I'm not sure if I can get it from there as I live in Canada. My question is when I see the R-0871 which is the titrating reagent (chlorine) and it is the drops . What comes up when I click on it is the powder (which I also need). Therefore i can't seem to find the R-0871 (which I really need). I must be tired or something.... sounds confusing eh?
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nope, didn't use the tub inbetween.
yesterday I added 9 oz. plus one tablesppon acid...did not go in, today FC was 2.0 and the pH was 7.8
I added10 oz, today and left the cover off for about half an hour. I thought I'd give it a while, then re-check to see where it's at.
I'm starting to think that perhaps I should use some MPS?
You definitely have a high chlorine demand. After two shocks it should have helped, but didn't seem to make a difference.
You can try giving it a dose of MPS. However, before you do get your FC to shock level (10-14 ppm). Make a note of where it is. Then shock with MPS (1 oz). Run the jets for 15 minutes and cover it up. Don't use the tub. Tomorrow check your FC, and see where it is. It should be > 6. Let us know your results.
Ok, I will do that right now.
Also, I have another question for ya..... I was going to order some replacement reagents and am having some trouble. I need R-0780 DPD powder R-0871 and CR-0004. I have found some sites, but the codes do not seem to match. The one site has R-0871 powder....strange indeed. I just don't want to order the wrong thing.
1 oz. of MPS is one tablespoon or teaspoon? Mine is granulated.
Nevermind the last question---- I figured it out. LOL
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I re-tested at 4:30 the next day. FC was 4 and pH was 8
I added 4 oz. of purox and 1 tblsp acid. I was expecting company, so did not want to add too much purox.
After the soak, I added another 10 oz.
Today, the FC was low (just used a strip first) and the pH was 8
I added 9 oz. of purox.
I will check the FC in a bit.
So, the night before last your FC was 16 ppm, then yesterday it was 4 ppm. You didn't use the tub in between this time, right? I'm still trying to determine why you still have a high chlorine demand.
nope, didn't use the tub inbetween.
yesterday I added 9 oz. plus one tablesppon acid...did not go in, today FC was 2.0 and the pH was 7.8
I added10 oz, today and left the cover off for about half an hour. I thought I'd give it a while, then re-check to see where it's at.
I'm starting to think that perhaps I should use some MPS?
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Thanks for the encouragement! Believe it or not I am enjoying this. Probably not so much if i didn't have so much help though!!!
Well, I went ahead and put in 10 oz. of Purox--yep 10. I left off the cover, ran the jets and areated (ran the water falls too)
I let it run for an hour, waited 15 min. then retested with the Taylor kit. The FC was 16. So, theoretically the FC should be above 8 by tomorrow night.
Remember, I checked the levels at 3:00 today, and did not add anything until 6:50 tonight, so the levels would have been lower than the 5.5 earlier today, (although I didn't check, as I have to order more replacements for the FC soon....)
I will check the FC again tomorrow by 3:00. I suppose I should have checked the pH after all that aeration, but I had company, and got distracted. I will check it now. Thanks again, really I just can't thank you and chem geek enough!!!!
There, I just tested the pH , and it is higher than 8.0 . That is 2 hours after adding the purox and aerating.
Well, your pH is > 8.0, because your TA is at 100. I wouldn't worry about that now though. Just close it up and let it sit overnight. Tomorrow check your FC and pH. If your FC is ~10 ppm like I'm predicting, you should be good as far as chlorine goes.
If your pH is still above 8.0, you can add some acid to bring your pH/TA down. Remember to be careful when cleaning with Baking Soda. As a matter of fact, only use Baking Soda as a last resort. You shouldn't need to use it all the time.
I re-tested at 4:30 the next day. FC was 4 and pH was 8
I added 4 oz. of purox and 1 tblsp acid. I was expecting company, so did not want to add too much purox.
After the soak, I added another 10 oz.
Today, the FC was low (just used a strip first) and the pH was 8
I added 9 oz. of purox.
I will check the FC in a bit.
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If I only add 6 oz. (which I add everyday) it will bring the FC up to 18? The purpose of the aerating is to raise the pH no?
I'm just thinking that by adding the usual 6 oz. which is just my maintenance amount, it will take a long time to raise the FC?
What about if I add 9 or 10 oz. tonight , plus aerate?
The reason why 6 oz is not raising FC enough is because your chlorine demand is high, because of the high bather load. i.e. your tub is using up FC as fast as you're putting it in. If we give it a good shock, that will lower your chlorine demand. If your demand is low, 6 oz should raise your FC by 15 ppm. If you're 3-4 ppm FC now, that should put you in the high teens tonight.
I don't recommend bringing FC up to 20 ppm for any length of time, very often, because it's not good for the cover etc. However, if you have a high demand, it won't stay high for long. The fact that you shocked it last night, and you haven't used it, I believe your demand is lower now. Therefore I predict you should have more FC tomorrow. If you add 6 oz tonight, let the jets run for 60 mins uncovered. BTW, the reason for letting your Jets run is to gas of some of the chlorine, so it's not too hard on your cover. Check FC 15 min after adding. You should have ~18 ppm. 24 hours later check FC again. I predict you should have ~10 ppm. If it happens they way I think it will, you should be good to go.
However, in the future you need to use more Purox. Your current amount (6 oz) is not enough to maintain with your bather loads. You might want to up it to 7 or 8 oz. Remember, don't go by how much Purox you put in, go by your FC levels. If it takes 8 oz to get your FC to ~12 ppm (shock level) so be it. It just means your tub is using more, and therefore you should give it more. Check FC 15 min after your add the Purox and 24 hours later. The 2nd reading should not be less than half of the first. So if you shock to 12 one day, and the next day it's 4, it's using more then it should and needs to be shocked again.
Remember your tub is safe as long as you keep a residual FC in it at all times. However, what we're getting into now is chlorine demand. You let you tub get behind. It's not big deal, it just needs a good shock. For the record, with your high bather loads, it's difficult enough to keep the tub safe, let alone keeping the chlorine demand down. I think you doing a great job.
Thanks for the encouragement! Believe it or not I am enjoying this. Probably not so much if i didn't have so much help though!!!
Well, I went ahead and put in 10 oz. of Purox--yep 10. I left off the cover, ran the jets and areated (ran the water falls too)
I let it run for an hour, waited 15 min. then retested with the Taylor kit. The FC was 16. So, theoretically the FC should be above 8 by tomorrow night.
Remember, I checked the levels at 3:00 today, and did not add anything until 6:50 tonight, so the levels would have been lower than the 5.5 earlier today, (although I didn't check, as I have to order more replacements for the FC soon....)
I will check the FC again tomorrow by 3:00. I suppose I should have checked the pH after all that aeration, but I had company, and got distracted. I will check it now. Thanks again, really I just can't thank you and chem geek enough!!!!
There, I just tested the pH , and it is higher than 8.0 . That is 2 hours after adding the purox and aerating.
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If I only add 6 oz. (which I add everyday) it will bring the FC up to 18? The purpose of the aerating is to raise the pH no?So, last night , after adding the other 4 oz. The FC read 13.Today at 3:00, I checked again, the FC was 4.0 the CC was 1.5 and the pH was 7.8.
The Purox was bought only about a week or so ago, however it could have been sitting on the store shelves here for a while, since very few folks have indoor pools!
A friend of mine just picked me up 2 more bottles on sale yesterday, so I've got about 4 and a half bottles of the stuff to go through before I get something perhaps stronger! It is pretty cheap all the same, so that doesn't really concern me all that much. Oh, and I waited 15 min. before checking the FC last night, and put the jets on for a wee bit to help mix it in.
I calculated pretty close at 14 ppm. That tells me your Purox is fine (it's not old). However, the fact that you only had 4.0 FC today means your tub is using too much chlorine. You need to shock it again. Add 6 oz Purox and let Jets/Air run for an hour before covering. That should bring your FC up to ~18 ppm. Check it 15 min later to make sure. Let it sit overnight and check FC again tomorrow. Let us know the results. I predict 10 ppm.
While your tub is safe to use (as long as you have FC in it), your chlorine is strugling to keep up, and is way behind. That means you need to use more chlorine in the future, and/or use MPS to help out. However, first you need to keep shocking it until your chlorine catches up. If it were me I would shock it everyday until it's caught up. That also means you shouldn't use the tub while shocking. If you shock to only ~12, it will take longer to catch up. That's why I recommend giving it a good whack to ~20. That should clear it up in a day or two.
I'm just thinking that by adding the usual 6 oz. which is just my maintenance amount, it will take a long time to raise the FC?
What about if I add 9 or 10 oz. tonight , plus aerate?
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And as for the CC, you can certainly see what happens after shocking with chlorine, but if it doesn't drop then I've got other things you can try, but we'll save that for later in case it becomes necessary. It's not a problem if you aren't smelling it -- so long as you measure FC, your tub is still sanitary.
So, last night , after adding the other 4 oz. The FC read 13.
Today at 3:00, I checked again, the FC was 4.0 the CC was 1.5 and the pH was 7.8.
The Purox was bought only about a week or so ago, however it could have been sitting on the store shelves here for a while, since very few folks have indoor pools!
A friend of mine just picked me up 2 more bottles on sale yesterday, so I've got about 4 and a half bottles of the stuff to go through before I get something perhaps stronger! It is pretty cheap all the same, so that doesn't really concern me all that much. Oh, and I waited 15 min. before checking the FC last night, and put the jets on for a wee bit to help mix it in.
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Thanks Nitro....... how much Purox should I put in to shock to 12 ppm let's say if the FC is at 3 ? It is usually about there when I test and before I add more Purox.
When you add your usual 6 oz, what does that bring your FC to?
Assuming your Purox is 10% Available Chlorine, 6 oz should add ~12 ppm to your current FC. However, if you add it after a soak, the FC will be used up, so you'll never get a good shock. So, what you need to do is add enough Purox to bring it to at least 12 ppm, and sustain that for a day.
If you want to do an experiment, try this one day when you don't plan on using the tub for a couple days.
Add 8 oz Purox. Assuming your tub is 380 Gal, that should add 17 ppm FC.
Run Jets/Air for a minimum of 30 mins (60 min would be better) uncovered.
Check FC and make note of it.
Cover and then check FC 24 hours later.
Let us know your results.
For instance:
Assume your FC was 15 ppm after shocking and running jets on day one.
The next day it should be at least 8 ppm, preferably 10 ppm.
If it's below 8 ppm, add 6 oz Purox to add ~12 ppm FC to your curent level.
Run Jets for 30-60 min uncovered.
Check FC and make note of it.
Cover and let sit for 24 hours.
Check FC.
You should be using less FC then the day before.
You want to get your tub using less than 50% (more like 25%) of FC per day with no use. My tub uses 25% FC. So if I shock to 12 ppm, the next day it will be 9 ppm.
Hmmm, well I don't believe that so far adding 6 oz. of Purox has put my FC up to 12, but I haven't checked as soon as I've put it in lately either!!! Today I put in 6 oz. (around noon) just now (10:45) I checked and it was 5.5, but I haven't been in it today. The pH was up to 7.8 by the way, with no use at all today.
The Purox I am using is 10.3% available chlorine and 10.8% sodium hypochlorite. I just added another 4 oz. for good measure. How long after adding the Purox should I re-check to see where the FC is at?
Oh yes, and I have saved the 'experiment' that you've sent along, and I will surely try that soon.
Hi Nitro And Chemgeek
in Hot Tub Water Chemistry
Posted
Thanks for your help.
Because I really don't think the hot tub is contaminated--I don't want to do a water change already. The test results have always been fine---I think I must have slipped up though last week, perhaps there wasn't as much in as I thought, for a short time. Right afterwards I added more Purox, and the next reading was still fine--so I never did get a 'bad' reading. I shocked it the next day, and used it several times over the weekend with no trouble. That is why I suspect that on the Wed. (before shocking with MPS, ) I had the problem. It was our two friends who woke up with a rash and they were itchy. I was fine.
My husband got the same rash he had last year. He has had the skin problem for a couple of months now atleast. The doctor told him it was excema, so I haven't been too worried about him (poor guy). It seems his problem has nothing to do with the tub. I am hoping that.
It would seem that I did not put in enough of the 20 Mule Team Borax. Also, what do I add to get Muriatic Acid in there? Crazy question, I know, but I want to be clear.
Next refill. I'll use the Gentle Spa substitute as I did last time.
Today's readings:
FC 3.5
pH 7.0
TA 70
I do the readings usually at the same time each day.
I have been aerateing to get the pH to rise, and it is now at 7.4 There seems to be a lot of foam though. This is another new development.